Image credit: Ryan Young/Cornell University
PROCESSING
In the lab, biologically derived polymer is grafted onto a plastic disc to demonstrate how it may be used in food packaging.
Developing active packaging to preserve food and reduce waste
C
ornell University scientists are finding ways to make active packaging materials that can address both the consumer demand for fewer preservatives and the environmental need for less plastic in packaged food. The latest research, which was published in June in the journal Food Packaging and Shelf Life, uses biologically derived polymer that helps salad dressings, marinades and beverages last longer in the fridge. “Active packaging gives us a new way to prolong shelf life despite consumer demands for cleaner labels,” said Ian Kay, a doctoral student in food science. “But it’s tricky. Foods and beverages have varying and complex composition, so we need to know a lot about the chemistry of the food and the active packaging to figure out which system works for which foods.” Joshua Herskovitz, who studied in the laboratory of Julie Goddard, professor of food science in the College of Agriculture and Life Sciences, grafted the corn-derived polylactic acid polymer with the antioxidant nitrilotriacetic acid to use it in food packaging. Kay, following up on Herskovitz’s work, figured out the material’s ‘interfacial pKa’, which tells you at which pH the foods in this packaging might work to keep from spoiling. As the antioxidant is bound to the polylactic acid, the preservative can interact with the food but not migrate into it. “In other words, you get the shelf-life benefit of the preservative without consuming it,” Goddard said. “This allows for cleaner label foods, which consumers are really looking for these days.” “As a food scientist, I’m excited about new ways to reduce food and packaging waste,” Goddard said. “I’m not antipreservatives as a whole, we need to remember things we use in the kitchen like heat, salt and lemon juice are important ingredients in food preservation. “So if we take preservative out of our food, at the same time, we need to think about the environmental impact if food spoils faster,” Goddard said. “Using a greener active packaging technique, we can extend shelf life while moving closer to a circular plastic economy.” www.foodprocessing.com.au
July/August 2022
33
